Electromagnetic fuel injection valve

Abstract

An electromagnetically actuated fuel injection valve includes a coaxial assembly of a connection tube, a bushing, a housing extension and a nozzle body. All seals between adjacent faces and edges of these elements are age-resistant metal-to-metal seals. The seal between the housing extension and the nozzle body is formed by pressing the overlapping end of the housing extension over annular edges on the nozzle body. The remaining seals are welds or solder-joints.

What is claimed is: 
     
       1. In an electromagnetic fuel injection valve for timed low-pressure fuel injection systems, which valve includes a coaxial assembly of a connection tube, a bushing, a housing extension and a fuel nozzle body, said assembly forming a substantially cylindrical passage for fuel to be delivered by said valve to an engine, the improvement comprising metallic seals between adjacent portions of said connection tube and said bushing, and between said bushing and said housing extension, said metallic seals having their surfaces in engagement with their corresponding adjacent elements under pressure, and a further metallic seal between said housing extension and said nozzle body, said further metallic seal being formed by parallel edges on said nozzle body which mate with an interior portion of said housing extension, and under external pressure embed themselves into the wall defining the interior portion of said housing extension. 
     
     
       2. A fuel injection valve as claimed in claim 1, wherein said bushing is a non-magnetic bushing disposed coaxially within the magnetic windings of said electromagnetic valve. 
     
     
       3. A fuel injection valve as claimed in claim 1, further including an armature, slidably disposed within a bore of said housing extension and a valve needle, fixedly and coaxially attached to said armature, the improvement further comprising said valve needle having a square transverse cross section in at least two separate locations; whereby fuel may flow over the flat exterior surfaces of said locations and over the remaining exterior surface of said valve needle. 
     
     
       4. A fuel injection valve as claimed in claim 1, wherein the metallic seals between adjacent portions of said connection tube and said bushing and between said bushing and said housing extension also serve to bond their respective adjacent elements to each other.